Telephone system.



TELEPHONE. SYSTEM. Y 1

APPLICATION FILED 311111121, 1909. EBEEWBD SEPT. 14. 1912.

1,105,344. mente@ July 28, 1914.

` E.. R. CORWIN.

A I TBLEY'HONE SYSTEM. APPLI'CATIoljt FILED J'U1 mz1,19os. BENBWED SEPT.14, 1912. 1,1 05, 344, Patented July 28,1914

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RR. CoRWN.

TELEPHONE SYSTEM. APPLIGATION FILED JUNE 2l, 1909. EBNEWED SEPT. 14,1912.'

Patenta July 28, 1914.

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, in other Words, that murs srn'rnsrnrnnr OFFICE. C

rimane n. convvIN, or CHICAGC, ILLINoIs, AssIeNoR, :er MESNEAssIGNMENTso- FRANK ie. 000K. COMPANY, or CHICAGO, ILLINOIS, A.CORPORATION or ILLINoIs TELEPHONE SYSTEM.

Application sled June 21, 1909, serial No. sucses.

To cl3 'wko/mf it may concern:

Be it known that ELMER l. Conn-'11s, a citizen y of the United States,residing at Chicago, in the county Vof Cook and State 'o f Illinois,have invented a certain new and useful Improvement in Telephone Systems,of Which the following is a. full, clear, ooncise, and exactdescription, reference being had to the accompanyin drawings, kforminglepart ofthis specification.

My' invention relates to' telephone ex# change systems, and has for oneof its objects the provision of s'telephone exchange systemfwherebycalling lines nre :automa-ticelly connected 'with responsive apparatusbelonging to operators that are not busy, or, nre4 at liberty tovzittend to the Wants of the calling subscribers.v

My invention, in its usual or most common embodiment, muy generally bedescribed as being e 'telephone exchange system including linesextending from Itelcphone stations to an exchange, s plurality of groupsof operators link connectorsat the exchange, responsive devicesfor saidgroup o link connectors, :and selecting mechanism governed by callinglines adapt-- ed to select responsive devices free for selection,ssid'link connectors. being adapted to their telephone'- line joiningfunction independently of the aforesaid selecting mechanism. In thepreferred embodiment of the invention the responsive devices control theassociation of conductors leading to the operators telephones und thereis preferably but one responsive device to each group of linkconnectors, though l'. do not Wish to be limited to thischziracteristic.A l have also provided operator Acontrolled means forfreeing the responsive devices so that they may be subject. to furtherselection.

I use the term groups of link connectors in the sense ot sets of linkconneet-ors' and with no regard to any segregation of the linkconnectors into physically distinct collections. y c

Myinvention-,Would beuse'ful in ,a very i small exchange since by meansof it signals` individual to the lines leading to the eX- chnnge :1renot required. A preferred form of telephone exchange systemaccomplishing this feature 'of my invention may generally be described:is including lines extending Specification of Letters Potent.`

with the 'groups vto the lines are in the form of phonographsPatenteduulyee; i914;

-Renewed September 14, 1912. Serial No. 'll

from telephone stations to an exchange, a piurulity of groups ofoperators link connectors .at the exchange for uniting lines inconversation'= a' responsive device for each group of link connectorsand desirbly common to the link connectors of' suchgroup, u

mechanism governed by vcalling linsfor operating the responsive devicesassociated of link connectors, vand means for rendering such responsivedevices .incapable ,of response whenthe 'operator in charge of" thegroup of link-*connectors is not at liberty to attend tothe. Went-s ofcalling subscribers. The rmeinsthat Sere eni-v ployed for thus renderingthe responsive de-v vices unresponsive a're furnished tofthe o `rator,to be used independently of the connectors and are furnished tothe oer-i ator to be used inl connection with 'the connectors, making aconnection orfis about tomke a connection, preferabl'yelso employ lmeansfor renderingy the -responsive devices unresponsive, that are governedby the mechanism that has selected a" responsive device, sb thatotherselecting mechanism will pass by the selected responsive device until itnds a responsive device lthat is free for selection.

s My invention also has for its; objecttli so that .while thef'operatoris' she will not be interrupted. I 75 provision of a signaling systemincluding a plurzilityA of signaling lines, such `ssteleh phone lines,signal receivers, 1 selector switches for selecting signal receiversthat are free for selection andassociating the same with signalinglines, vidual to the lines and which differ 'from each other forvcausing said signal receivers to give characteristic signals peculiartothe lines; .Inthe preferred embodiment of the invention the ineens whichare indivi/"iidnel,gA

capable of speaking the numbers offthe lines to which' they areindividual, -in Whchidve'nt the signal receivers nrc in the formo-foperfe ators head telephones to `announce to operator the numbers ofthe lines; f

I will explain my inventibn, in its-.vsn

aspects, more fully by reference ,to"tlxetir-A compnnying drawings,showing oney eJnbdd'l Figure l'is a general diagrammatic illustrating ssystem constructed in accordl ance with my invention. Figs. 2 and?) repibeing illustrated with this apparatus.v The' telephone lines, in theembodiment of the invention illustrated, each terminate 'at the exchangein multiple jacks 6. I have illustrated 1n the drawings, linkconnectors, each including, in the embodiment of the inventionillustrated, an answering plug 7 and a connecting plug 8, these plugshaving tip,`

sleeve, and thimbley or heel contact parts lunited by 'correspondingstrands. I do not wish to 4be limited, however, in all embodiments of myinvention to link connectors employing answering plugs as wellasconnecting plugs nor lto the use of connecting plugs. The circuits ofthe link connectors are immaterialto the preferred embodiment of myinvention. They may be of any well known or suit-able type, and I willdescribe 'none of the apparatus peculiar to the link.

connectors, exceptin to state that each ot the link connectors shown isadapted, when connected at its ends with calling and called lines, tounite such lines in` conversation. For like reasons, I have omitted theillustration of parts commonly found in association with linkconnectors, such, for example, as supervisory signals and signalingcurrent generating apparatus.

In Fig. 1 of the drawings, I have illustra-ted, at A, but one linkconnector of a group belonging to one operators position and, at B, Ihave illustrated one link connector of a group belonging to anotheroperators position. A

In Fig. 2, I have shown, at A, a link connector of a group belonging toone operators position van at B, I have shown a link connector of agroup belonging to another operators position. At each operatorsposition, I have shown a responsive device 8 common to the group of linkconnectors at such operators position, this responsive device preferablyconstituting a signal-actuating device, the responsive device atposition A governing the circuit of a small lamp 9, while the responsivedevice at station B governs the position of a mechanical display element10. Y

'I interpose apparatus between the :responsive devices and the telephonelines whereby a calling telephone line may operate a responsive' deviceythatis free for operation,

instrumentalities being employed to prevent the responsive devices fromoperating when the operator at the position having such responsivedevices is not free to perform work.

In the embodiment of the invention illustrated, I employ selectingmechanism individual to l-the telephone lines and set into operation bya calling line for the purpose of operating a responsive device, such asan 'foperators head telephone or a signal device 1n response vto whosesignal the operator may', in any preferred way, be brought intotelephonie connection with the calling subscriber, either automaticallyor by a listening key, the responsive device being tree for operation,thereby calling the attention of the operator having such responsivedevice,

so that such operator may effect connection between the calling andcalled lines.

I will first give a description of the selecting mechanism associatedwith each line, andV will thereafterdescribe its inter-relation .withthe line and with the responsive devices.

The selecting mechanism illustrated includes a ratchet wheel 11, uponwhose shalt Aa single group of wipers 12 121 122 are carried',` thesewipers 12 121 122being adapted to contact with waiting contacts 13 131132 associated with the responsive 'devices 8. Each responsive devicehas a plurality ofgroups of waiting contacts', each group containingthree contact-s 13 131 132. Similarly related waiting contactsassociated with va given responsive device are in multiple connection.-The groups of waiting contacts belonging to each responsive device aredistributed among ioo the selecting devices, so that'the wipers| of theselecting devices in their travel will engage one group of waitingcontacts belonging vto one vresponsive device or another group ofwaiting contacts belonging to another responsive device, or anothergroup of waiting contacts belonging to still another responsive device,and so on. A magnet 14 is provided with an armature -15 pivoted at' 16,said armature, when attracted, causing the actuating pawl 17 carriedthereby to rotate the ratchet wheel 11 one tooth, the pawl escaping thetooth when the armature isrestored, as will be seen by the illustration.The winding of the magnet.14 is included in circuit with an interrupter18 common to the selectors, and a source of current 19, which may be thegrounded common battery of the exchange. The magnets 14 are individualto the telephone lines, and in addition to their circuits including theinterrupter 18 that is common to all ofthe magnets 14, said circuitsalso include the lowermost normal contact'20 of the locking relay 21,the lowermost normal contact 22 of the cut-olf relay 23, one side of thecalling subscribers line,t the calling subscriber-s transmitter 3,receiver 2, switch-hook 1, the remaining side ofthe calling subscribersline, to the grounded im- 13o are brought to pedance 24. During a partof the time that the selecting mechanism is in association' with aselected' responsive device, the locking relay 21 and the cut-off relay23' remain inert.

,It will thus be seen that as soon as a calling subscriber has lremovedhis receiver from its switch-hook,` theselecting mechanism individual tothe calling subscribers -line is set into operation, and immediatelyafter the selecting mechanism has been set into operation a circuitincluding the bat.-

tery 1'9, is Iclosed at the contacts 25, which gether as a consequenceof the initial operation of the selecting mechanism, whereby battery 19is connected with the testthimbles 2G of the jacks belonging to thecalling line, so that no operator, eX- cepting theone that is to beselected, will connect with a calling line. The wipers of the selectingdevices are desirablynormally out of contact with the contacts .13 131'132 and pass over these contacts in the process free to be operated.Thus responsive devices are free for selection when the circuitsgoverning the responsive devices are in their normal or idle conditions.Each responsive device has a governing circuit that may be traced fromthe ground 27, the manually controlled switch 28 (designed for operationby the operator to render responsive devices unresponsive), the armatureswitch of magn-et-29, the armature switch 30 of the responsive device 8,the engaged waiting con- Y tact 13, a wiper 12 resting in engagementtherewith, the

follow-up contact 31, the armature switch spring engaging the same,

-the locking relay 21, to the grounded battery The ground 27 is presentas a part of such controlling circuit when the responsive deviceassociated therewith is to be actuated,

butwhen the responsive Adevice is not to be selected, this ground 27 isto be removed, which removal may be accomplished in several' ways, aswill appear. Assuming the ground 27 to be present in the circuitcontrolling the associate responsive device 8, the

selecting mechanism of the calling subscriber will cease operation assoon as its wiper 12 engages the waiting contact 13 connected with suchground 27, to maintain said wiper and contact in engagement and also tomaintain the wipers 121 122 in engagement with the waiting contacts 131132 of the selected group of waiting contacts, in order that circuitchanges may be effected which remove the ground 27 from a selectedresponsive dei/ice and willv prevent the further operation of theselecting mechanism, and also preferably to enable the operator to havetelephonie connection with a calling subscriber independently of thelink connecting apparatus. As a consequence of the circuit closed by wayof. the elements 12 1.3,

the armature switch spring engaging the normal contact 31 is moved toengage its grounded alternate contact, whereby circuit.

locking relay 21,the wiper 122 is connected twith one side of thecalling line and the wiper 121 is connected with the other side of thecalling line, and inasmuch as the contacts 131 132 engaged by the wipers121 1.22 are preferably connected with the operators telephone equipment32 or conductors leading thereto, such operatorls telephone equipment orthe set of conductors leading thereto is selectively brought intocircuit relation with the calling line preferably independently of thelink connecting apparatus 7 8.

The operators telephone thus constitutes a responsive device common toits group of link eonectors and which is not necessarily operated as aconsequence ofits selection but is permitted to be operated by thecalling party when speakinginto his transmitter.

In order to prevent another selecting mechanism belonging to anothercalling linev from picking out a selected responsive device, in the lormof an operators telephone or relay 8 that has become associated with acalling line, line 120, for example, the ground 27 is removed, thecircuit that effects the removal of the ground 27 lbeing traceable fronithe grounded battery 19 to the responsive device 8, the waiting contact131, the engaging wiper 121, the alternate contact 88, the normalcontact 22, one side of the subscribers line,through the subscribersstation, the other side of the subscribers line, to the groundedimpedance device 24. The magnet of the responsive device 8 is thusenergized to cause its armature switch 30 to leave its contact, andthereby separate the ground V27 from the normal contacts 13, whereby thewiper 12 of any other selecting mechanism will pass by said waitingcontacts 13, inasmuch as no circuit is establishable-for the lockingrelay 21 of the calling line belonging to the other selecting mechanism.In order that the operator may have control over the responsive devices8, to determine whether or not they are to be selected, she is not onlyprovided with the manually operated switch 28 for her responsive device,but her link connectors are also provided with mechanism that 'governs'the association, of the ground 27 with the waiting contacts 13.

' In the preferred embodiment of the invenioo los

tion, each end of the link circuit has an i electro-magnet 341, 34:8,the armature switch of each of which having a single normalcontact andtwo alternateeontaets, the, 11p- 180 per one of which enters into thepreferred embodiment of my invention. Each magnet 3&3 has a localcircuitwhich is established when theplug associated therewith is inserted ina-jack, the circuit for each electromagnet 343 then being traceable fromthe, grounded battery 19 through the winding' of -magnet 343, the heelcontact 3&1 of the associate plug, the thimble of the jack receivingsuch plug, to the grounded cut-oft' relay 23. The normal contacts ofboth magnets of aolink connector or cord Circuit normally coperate toestablish a dead circuit. Then one of the plugs only is in engagenientwith a jack, this dead circuit is broken and a live circuit for themagnet 29 is established, which' may be traced from the groundedterminal of the magnet 29, through the listening key-operating magnet35, the normal contact of the inert mate to the operated-magnet 343, theupper alternate contacto the energized electro-magnet 34:3,

to the grounded battery 19, whereby the magnet 29 is-energized, itsarmature switch is attracted, and the ground 27 is removed from thewaiting contacts 13, so that a selecting mechanism of a callingsubscriber is.

bound to pass by the waiting contacts 13 associated'with the responsivedevice 8 from whose governing circuit the groundf27 has thus beenremoved. Thus the operator, in using one plug of a link connectoremploying two plugs, will prevent the selection of 4vthe responsivedevice common to the group of link connectors that includes such linkconnector which l as been takenfor use. As

soon as the operator has inserted the connecting plug of the linkcircuit taken'for use, the right hand relay 343 is energized,

thereby breaking the vcircuitA for the magnets 29 and 35 causing theoperators telephone to be disconnected from the employed link circuitand causing Aa restoration of the ground-*21m the circuit thatgovernsthe device to an operators position, though .I do not wish to be limitedto this characteristic.

Vhen the answering end of a link connector circuit has been connectedwith a calling line, the wipers of the selecting mechanism of Suchcalling line are desirably shifted out of engagement with the waitingcontacts, releasing` the responsive device so far as the selectingmechanism is concerned. To thisend, I employ a releasing electrolmagnet36, a circuit for which is established when the connecting. end ofthe'link circuit selected by the operator has been connected with thecalling line, and which circuit may be traced rom'the grounded battery19` through the operated 'switch 25, the releas- 'ing magnet- 36, andthe closed armature switch 37. When the circuit of the releasing magnet36 is-Hthus closed, it withdraws. the actuating pawl l17 from theratchet wheel 11, permitting lsaid ratchet -wheel to be moved toa'position in which Vthe wipers 12 121'122 are out of engagement withwaiting contacts. As soon as the wipers are placed out of contact withwaiting contacts, the switch 25 is opened and the circuit ofthereleasing magnet 36 is consequently broken,

whereby said magnet permits the rengagei ment of the holding andactuating pawls 17 with the ratchet wheel 11. The switch 25,whenopen'ed, also breaks the circuit for the locking-magnet 21 and-alsoremoves Vthe batteryv 19 from connectionwith the test thinibles 26 bywayof the switch 25, substitute connections with the thimbles 26 be'-i'ng established for testing purposes by the cord circuits, inaccordancewith common practice. When the subscribers are throughconversation, the operatoi` will take down the link connector employedtounite the subscribers lines, whereupon the apparatus will becompletely restored to the normal condition illustrated'.`

ltwill be apparent from what has been described, that each responsivedevice which. is common to a group -or link connectors has a'pluralityof groups of waiting contacts, similarly vrelated waiting contacts ofthe different groups being in multiple connection, the di'iferent groupsof waiting contacts being distributed among lthe selectingdevices, eachselecting device thus having one group of waiting contacts belonging tovone responsive device, another group .of

waiting contacts belonging to another re-V sov sponsive device, a thirdgroup of waiting c contacts belonging to a third responsive device, andso on, the wiping contacts engaging one group of waiting contacts andresting in engagement therewith if the circuit governing the responsivedevice associated with said waiting contacts has its normalgroundconnection 27, but 'passing out of connection with such waitingcontacts if such ground 27 is removed, the wipers continuing to moveuntil they haveencountered a group of contacts one ot.A which has theground 27 connected therewith. Thus a calling subscriber or Vothercalling party, by setting his selecting mechanism into operation, willassociate himself with an operator who is -in position to answer hiscall. The system of my invention, therefore, is of great importance, in

Work that she is to perform.

Each operator desirably has an ample number/ of cord circuits assignedto her rvhichfare preferably equal to or slightly in 'excess 4of thenumber-that she can handle (f when she is operating-'at her fullesteililciency. If she has used all of the cord circuits that have beenassigned to her, she lf will temporarily shift the switch 28 until someof her cord circuits arev released and y1g; taken down, whereupon shewill restore the switch 28 to its closed position. If it is desired .totake operators off of duty, the switches. 28 of such operators areopened. In this Way the business of the exchange may be assigned to thenumber of operators that are capable of handling it, a lesser number ofoperators being required during the lighter periods of the day and moreoperators being required during the heavier g5 periods ofthe day, -allas will be apparent.

It is further obvious that With the system of'iny invention 'main andintermediate distributing boards may be dispensed with, line, signals,in fixed association with the linesg -30 may be discarded, as well-asthe answering jacks of such lines When the invention is employed inconnection with multiple switch boards. l

In the preferred embodiment of the inven' g5 tion, I do not use manuallyoperated listen-` ing keys, .but cause the magnets to op erate'listeningkeys 351, these magnets 35 causing the operators telephone equipment `32to be included incircuit when the link,l

40 connectors are connected ,with calling lines,`

so that the-operator mayfconverse with thel calling subscriber. Theseresults are accom-` plished in connectionfivith responsive devices, oneherein shown as being provided for each operator andcommon to her group'pf connectors, but I do not Wish to be limited to responsive devicesthat are thus common ,to groups of link connector Initially, as has beenexplained, the operators Itelephone equipment is connected with acalling line by means of the selecting mechanism of the calling line,and inasmuch as there may be no line signals in fixed association withthe lines. the operator Will not have the facilities aiforded'by suchline signals for informing her as to the numbers of thecalling lines.She may ascertain the number of the calling line by conversing with thecalling subscriber through the tele- 'phonic circuit established by theselecting mechanism, or if it is desired to relieve the callingsubscriber of the burden of inform- A,ing the operator of his number,aphono- 'graph 38, one' per line, and preferably-con- 435 stantlyoperating, maybe employed. to speak pression l mean that the responsivedevices are associated with the link connectors.` I do not limit myselfto any circuit association between Vthe link connectors and thersponsive devices.

lVliile I have herein shown and particularly described the preferredembodiment of my invention, I do not Wish to be limited to the precisedetails of construction and circuit arrangement shown, but,

Having thus described my invention, I claim as new and desire to secureby Letters Patent the following l. A telephone. exchange systemincluding lines extending from telephonestations to an exchange, aplurality of groups of operators link connectors at the exchange foruniting lines in conversation, an operators telephone outfit for eachgroup of link connectors and common to the link connectors of suchgroup, selecting mechanismA governed. by calling lines adapted to selectand permit the operation of the operators telephone outfit free to beoperated, means made effective by the link connectors of each gro-upthat are taken for use to prevent the responsive device associated withsuch group Irom being selected ior operation, and mechanism governed bythe connecting ends oit the link connectors and serving, When taken foruse, to release the operators tele- `phone outfits, again to render themfree for selection by the calling lines.

A telephone exchange system including lines extending from telephonestations to an exchange, a plurality of groups of operators linkconnectors at the exchange for uniting lines in conversation, aresponsive device for each group o't' link connectors and common to thelink connectors of such group, selecting mechanism governed by callinglines `adapted to select and permit the operation ofthe responsivedevice free to be operated, means made efl'ective'by the link'connectorsof each group that are taken for use` to prevent the responsive deviceassociated with such group from being selected for operation, operatorstelephones for the groups of link connectors, switching means governedby the selecting mechanism and actuated by operated selecting mechanismto bring the operators 'telephones asfor uniting lines in conversation,an operators telephone outfit for each group of link connectors andcommon to the link connectors of such group, selecting devicesindividual to the telephone lines and operated by lcalling lines toselect andgpermit the operation of the responsive device free to beoperated, means made eective by the link connectors of each group thatare taken for use to prevent the operators telephone outi'it associatedwith such group from being selected for Operation, and mechanismgoverned by the connecting ends of the link coniiectors and serving,when taken for use,' to release the operators telephone outiits, againto render them free for selection by the calling lines.

4. A telephone exchange system including lines extending from telephonestations to an exchange, a plurality of groups of .operatorslink-connectors at tlie`exchange for uniting lines in conversation, aresponsive lected responsive devices into telephonic'as-- `isis devicefor. each group of link connectors and common to the link connectors ofsuch group, selecting devices individual to| the telephone lines andoperated by calling liiies to select and permit the operation of theresponsive device free to be operated,-nieans made eii'ective by thelink connectors of each group that are taken for use to prevent theresponsive, device associated with such group from being selected foroperation, operators telephones for the groups of link connectors,switching means governed by the selecting mechanism and actuated byvoperated selectingvmechanism'to bring the operatorstelephones associatedWith the sesociation with the calling lines, and mechanism governed bythe connecting ends of the link connectors and serving, when taken foruse, to release the responsive devices, again to render them free forselection by the calling lines.

5. A telephone exchange system including lines extending from telephonestations to an exchange, a plurality of groups of operators linkconnectors at the exchange for uniting lines in conversation, anoperators telephone outfit for each roup oflink connectors and common totie link connectors of such group, selecting mechanism governedbyncalling lines adapted to select and permit the `operation ot theoperators telephone outfit free to be operated, and means made effectivelby actuated selecting mechanism to prevent operators telephone outfitsfrom being again selected While in operated conditions. Y

6. A telephone exchange systemincluding f, lines extending fromtelephone stationsto an exchange, a plurality of groups of operatorslink connectors at the exchange fory uniting lines in conversation, anoperators telephone outfit for each group of link connectors and commonto the link connectors of such group, selecting devices individual tothe telephone lines and operated by calling lines to selectand permit,the operation'of the operators telephone outfit free to be operated,and means made eiiective by ac- 'tuated selectingdevices to preventoperators telephone outfits from being again selected While in operatedconditions.

7. A telephone exchange system including lines extending from telephonestations to an exchange, a plurality of groups of operators linkconnectors at the exchange for uniting lines ink conversation, aresponsive device for each group of link connectors and common to thelink connectors of such calling lines adapted to select and permit theoperation of the responsive device free to be i operated, means madeeiiective by the link connectors of each group that are taken for use toprevent the responsive deviceA associated With such group from beingselected for operation, and mechanism governed by the connecting ends ofthe link connectors and serving, ivhen taken for use, to release theresponsive devieesLagain to render them responsive to the mechanismgoverned byy the calling lines, the selecting mechanism having contactsand said responsive devices having contacts adapted for engagement Withthe aforesaid contacts, said responsive devices having the circuitscontrolling the Asame altered when the contacts of responsive devicesfree to be selected are engaged by the selector contacts and said meansbeing in the forni of switching devices serving to render ineifectivethe controlling circuits of responsive devices that are not tobe free/to be selected.

8. A telephone exchange system including lines extending from telephonestations to an exchange, a pluralit)Y of groups of operators linkconnectors at the exchange for uniting lines in conversation*` aresponsive device for each group of link connectors and eonnnon to thelink connectors of such group, selecting ineehanisni governed by callinglines adapted to select and permit the ope 'ation o'f the responsive4device free to be loperated, means made ellective b v the linkconnectors of each group `that are taken for use to prevent theresponsive device associated with such group from being selectedgoverned by the selecting mechanism anding lines extending fromtelephone stations to an exchange, a plurality of groups of op *eratorsllink connectors at the exchange for group,'s"electing devices individualto the telephone lines and operated by calling lines for operation,operators telephones for jthc! groups of link connectors, switchingmeans actuated by operatedselecting niechanism'to bring the operatorstelephones associated with the selective responsive devices intotelephonie association-'With the calling lines, and mechanism governedby the connecting.o ends of the link 'connectors and serving, when takenforuse, to release the responsive devices, againto'render themresponsive to the mechanism governedA by the calling'lines, theselecting mechanism having contacts and' said responsive devices havingcontacts adapted for engagement with the aforesaid contacts, saidresponsive devices having the circuits controlling the same altered whenthe contacts of responsivedevices free to be selected are engaged by theselector contacts and ysaid means being in the form of switclr ingdevices serving to render ineffective thel controlling circuits ofresponsive devices that are not to be free to be selected.

9. A telephone exchange system including lines extendingy :fromtelephone stations to an exchange, a plurality of groups of operatorslink connectors at the exchange for` uniting lines in conversation, aresponsive device for each group of link, connectors and common to thelink connectors of Such group, selecting devices individual tov thetelephone lines and operated by calling lines to select and permit theoperation of the responsive device free to be operated, means madeeffective by the link connectorsof each group that are taken' for use toprevent the responsive device associated with such group from'beingselected for operation, and mechanism governed by the connecting ends ofthe link connectors and serving, when taken for use, to release theresponsive devices, again to render them responsive tothe mechanismgoverned by the calling lines, the selecting devices having lcontactsand said responsive devices having contacts adapted for engagement withvthe aforesaid contacts, said responsive devices having the circuitscontrolling the same altered When the contacts of responsive devicesfree to be selected are engaged by the selector contacts and said meansbeing in the form of switching devices serving to render ineffective theconL trolling circuits of responsive devices that are not to be free tobe selected.

l0. A 'telephone exchange' system includuniting lines in conversation, aresponsive device for each group of link connectors and common to thelink connectors of such .l

to select and permit the operation of the responsive device .free to beoperated, vineens fronibeing-' selected/l. for operation, operaltorstelephones-for the groups of link connectors,"- switching4 meansgoverned by the selecting-zi'n'echanism and actuated by opermadeeiectivefby thiejlink connectors of each .group.ji'liajt are` taken foruse'lto ,prevent the responsivefdevice, associated. with such group.

ated selecting mechanism to bring the operators-telephones associatedwith the 'selected irespon's'ive: devices 'into telephonie associaf vtionl ,with `fthe calling" lines, and mechanism 'governed by theconnecting ends fof the link ccnnect'ors and serving, when takenfor-use,

torelease the responsive devices, again' to vrender them responsive tothe mechanism governed bythejcalling lines, the selecting devices havingcontacts-'and said-responsive devices-having contacts 'adaptedforengagement Withlthe aforesaid contacts, said responsive deviceshavingthe circuits controllingv the-same altered when the contacts ofvresponsive devices free to beselected are engagedl the selectorcontacts and said.

means being i-n the' form of switching devices serving to renderineffective the controlling .circuits of@ responsive devices thatare-not tofbelfree tobe selected.. A

1L A;telephone"exchange system includ ing linesiextending. fromltelephone stations to an''xciiange, a plurality of groups of operatorslink vconnectors at the exchange for uniting lines in conversation,v aresponsive device for each group of link vconnectors and common to thelink connectors of such group, selecting mechanism governed -by callinglines adapted Hto select and permit the operation of the responsivedevice free to be operated, and means governed by the operators toprevent responsive devices from being selected for operatiomltheselecting mechanism having contacts and said responsive devices havingcontacts adapted for engagement with the aforesaid contacts, saidresponsive devices having theicircuits controlling the same altered whenthe contacts of responsivedev'ices free to be selected are en# gaged bythe selector cont-acts and said means being in the form of switchingdevices serving to render ineffective the controlling circuits of`responsive devices that are not to be'free to be selected. j

12. A telephone exchange system including lines extending from telephonestations to an exchange, a plurality of groups of operators lilikconnectors at the exchange for uniting lines in conversation, aresponsive device for each group of link connectors and common to thelink connectors of such icc group, selecting devices-individual tothe s*"telephone linesand operated by callinili'nes to select and permit theoperation of there-- sponsive device free to -b'e '.operated, and meansgoverned bytheoper'ators to prevent responsive devipcs. from beingselected for operation, the selecting devices` having conisc i vtactsand said responsive devices having -contacts adapted for engagement withthe laforesaid cont-acts,"said responsivedevices' having vthecircuits`controlling the same altered-when the contacts of'responsivedevicestreetobe selected are engagedby the selector contacts and saidmeans being in the form of switching deviccs serving to renderinelective the controlling circuits of responsive-,devices that are not`to be free to be t selected.

13.. A telephone exchange system includ inglines extending fromtelephone stations t'o'an exchange," a plurality of groups of opcraterslink connectors at the exchange for uniting lines in conversation,aresponsive deviceforeach group of linkI connectors and ``common to thelink connectors of such group, (selecting mechanism governed by callinglines adapted to select and permit the operation of the responsivedevice rree to be operated, and means made eective by actu- I atedselecting mechanism to preventthe reof responsive devices free to vbe.selected are engaged by the. selector contacts arid said means being inthe form of switching devices serving to render ineffective thecontrolling circuits of responsive devices that vare not to bc free tobe selected,

1455A telephone exchange system including lines extending from telephonestations Vto an exchange, a pluralityo'f groups of operators link'connectors vat the exchange for uniting lines in conversation, aresponsive device kfor each group of link connectors and common to thelink connectors of such group, selecting devices individual to thetelephone lines and operated by calling-lines to `select and permit theoperation of the responsive device free to' be operated, and means madeeffective by actuated selecting devices to prevent responsive devicesfrom being again selected While in 'operated conditions, the selectingdevices having contacts and said responsive devices lhaving .contactsadapted for engagement with the aforesaid contacts, said responsivedevices .having the circuits controlling the same altered .when thecontacts of responsive devicesfree to be selected are engaged by thevselector'contacts and s aid means being in the forml of switchingdevices serving -to render ineffective the controlling circuits ofresponsive devices `that are not to be free to be selected'.

l5. A telephone exchange" system including lines extending fromtelephone stations to an` exchange, a plurality of groups of operatorslink connectors at the exchange -for uniting lines in -conversatiomanoperators telephone outiit Jfor each group of link vconnectors andcommon-to the link 'connectors of such group, mechanismgoverned bycalling lines adapted to permit the operation of the operators telephoneoutfit free to be operated, means made e'ectiveby the link connectors ofeach group that are taken tor use to prevent the operators. telephoneoutfit associated With such group from being operated, and mechanismgoverned by the connecting ends of' the link connectors and serving,When taken for use, to release the operator-s telephone outfits, againto render them responsive to the mechanism governed by' the callinglines.

16A A telephone exchange system including lines extending from telephonestations to an exchange, a plurality of groups of operators linkconnectors at the' exchange for uniting lines in conversation, aresponsive device for each group of link connectors and common to thelink connectors of such group, mechanism governed by calling linesadapted to permit the operation' of the responsive device free to beoperated, means .made eiiective by the link connectors of each groupthat are taken for use to prevent the responsive device associated withsuch group from being operated, operators ,telephones for the groups oflink connectors, switching means governed by the mechanism and actuatedby operated mechanism. to bring the operators telephones associated withthe responsive devices into telephonie association with the callinglines, and mechanism governed by the connecting ends of the linkconnectors and serving, when. takenI for use, to `release the responsivedevices, again' to render them responsive, to the mechanism governed bythe calling lines. i

17 A telephone exchange system includi'ng lines" extending fromvtelephone stations it'o an exchange,l va plurality of groups ofoperators link connectors at the exchange for uniting lines inconversation, a responsive device for each group of link connectors andcommon-to the link connectors of such groupmechanism governed by callinglinesadapted to permit the operation of the responsive device free to beoperated, means made eiective by the link connectors of each lgroup thatare taken for use to prevent the responsive device associated with suchgroup vfrom 'bei-ng operated, and mechanism governed by the connectingends of the link connectors andserVing, when taken for use, to releasethe' responsiveI devices, again to render them responsive to themechanism governed by the calling' lines,the rst aforesaid mechanismhaving contacts and said responsive devices having contacts adapted forengagement with the aforesaid contacts,

said responsive devices having the circuits 1adapted to permitcontrolling the samealtered when the conL tactsof responsive .devicesfree to be operated are engaged by the contacts and said 'eratorslinkconnectors at the exchange for uniting lines in conversation, aresponsive device for common to .the link connectors of .such gqoup,mechanism governed by. calling lines the operation of the responsivedevice free to be operated, means made'eiiiective'by the link connectorsof each group that are taken for use to prevent the responsive deviceassociated with such group from being operated, operators telephones forthe groups of link connectors, switching means governed by the mechanismkand actuated operated mechanism to bring the operators telephonesassociated with the ie' sponsive devices into telephonie associationwith the calling lines, and mechanism governed by the connecting ends ofthe link f connectors and serving,

`to release the responsi ywhen taken for use, ve devices, again torenderthem responsive to the mechanism governed by the calling lines,the first aforesaid mechanism having contacts and said i. responsivedevices rhaving contacts adapted device for each oxfor engagementWitlitheaforesaid contacts,

Said responsive devices having the. circuits controlling the sainealtered when the contacts of responsive devices free to be operated areengaged by the contacts and said means being in the form of switchingdevices serving to render ineffective the controlling circuits ofresponsive devices that are not to'be free to be operated.

19. A telephone exchange system including lines extending from telephonestations to an exchange,

a plurality of groups of operators. link connectors at the exchange for4unit-ing lines .in conversation, a responsive group of link connectorsand common to the link connectors of such group, mechanism governed bycalling lines yadapted to permit theoperation of the responsive devicefree to be operated, and means governed bysthe operators to preventresponsive devices from being operated, the aforesaidmechanism. having''contacts and said responsive. vdevices having. contacts adapted. .forengagement witlirthexapforesaid contacts, `responsive devicesghaving-thecircuits'. controlling thesaime altered when the contacts of.responsiicydevices freetobe operated. are/.engaged by `the contactsandsaidmeans being in the` formof sit',itching devicesseiving to renderineifectivetheponf n adapted each group of link connectors and trollingcircuits of responsive devices that are not to be free to be operated.

20. A telephone exchange system including lines extending -fromtelephone stations to an exchange, a'plurality of groups of operatorslink connectors at the exchange for uniting lines in conversation, aresponsive device for each group of link connectors and common to thevlink connectors of such group, mechanism governed by calling lines topermit the operation of the responsive device free to be operated, andmeans made effective by actuated mechanism to prevent responsive devicesfrom being again taken for operation while in operated conditions. theaforesaid mechanism having contacts and said responsive devices'. havingcontacts adapted for engagement With the aforesaid contacts, saidresponsive devices having the circuits tered when the contacts ofresponsive devices freev tobe operated are engaged by the contacts andsaid means being in theform of switchinff devices serving 'to renderineffective'the controlling circuits' of .responsive device'sthat arenot to be free to be operated.

21. A telephone exchange system including lines extending from telephonestations to an exchange, a plurality of groups of operators linkconnectors at the v'exchange for uniting linesin conversation, arespon-` sive device for each group of link connectors and common to thelink connectors of such group, switching mechanism governed by callinglines adapted to permit the operation of the responsive device free tobe operated, and means made effective by actuated switching mechanism toprevent responsive devices from being again taken for operationwhile inoperated conditions, the aforesaid mechanism having contacts and saidresponsive devices havingcontacts adapted for engagement vwith theaforesaid contacts,

said responsive devices having the circuits controlling the same alteredwhen the contacts ofresponsive devices free to be opercontrolling thesame alated are engaged by the contacts and said means being in the formof switching devices serving to .render ineffective lthe controllingrcircuits of responsive devices that are not to be free to'be operated.

22. A telephone exchange system including lines extending fromtelephonestations 4 a pluralityof groups of to an exchange,

at the exchange operators?. link connectors for uniting? .lines -inconversation, a responsive-device foreach.. V oup of link connectorsandcommon to ge link connectors vof such roup,.selectjngmechanismgoverned by .reallng lines. tedio. .selfst andi per-f.-

mitthex operation/ o reSponSiYeyice 'tre to. be operated andT ineens.::for nre- .venting responsiveA .d vices [-.froiii i being. selected for.operation,

nism having contacts and said responsive devices having contacts adaptedfor engagement with the aforesaid contacts, said responsive deviceshaving the circuits controlling the same altered when the cont-acts ofresponsive devices free to be selected are engaged by the selectorcontacts and said means being inthe form of switching devices serving torender ineffective the controlling circuits of responsive devices thatare not to be free to be selected.

23. A telephonel exchange system including'lines extending fromtelephone stations to an uexchange, a plurality of groups of operatorslink connectors at lthe exchange for uniting lines in conversation, arespon` sive device for each .group of link connectors and common to thelink connectors of such group, selecting devices individual to thetelephone lines and operated by calling lines to select and permit theoperation of the responsive device free to be operated, and means forpreventing responsive devices :trom being selected for operation, theselecting devices having contacts and said responsive devices havingcontacts adapted for engagement withthe aforesaid contacts, saidresponsive devices having the circuits controlling the same alteredWhenth'e contacts ci' responsive devices tree to be selected areengagedv by Lthe selector contacts and said means being in the form ofswitching devices serving to render ineffective thereontrolling circuitsof responsive devices that are not to be tree to be selected.

Q4. A telephone exchange system including lines extending from telephonestations to an exchange, a plurality of groups of operators linkconnectors at the exchange tor uniting lines in conversation, aresponsive device for each group of link connectors and common to thelink connectors of' such- 4 group, 4adapted to permit mechanism governedby calling lines the operation of the responsive device free to beoperated, and means for preventing responsive devices from beingoperated, the aforesaidmechanism having contacts and said responsivedevices having contacts adapted for engagement with the aforesaidcontacts, said responsive devices having the circuits controlling thesame altered when the contacts of responsive devices vifree to beoperated are engaged bythe contacts and said means being in the form ofswitching devices serving to render inettective the controlling circuitsof responsive devices that are notl to be free to be operated p Atelephone exchange system including lines extending from telephonestations to an exchange, a plurality of groups of operators linkconnectors at the exchange for uniting lines in conversation, aresponsive device for each group of linkconnectors and common Vto thelink connectors of such erated responsive device Y lines adapted group,selecting mechanism governed by calling lines adapted to vselect andpermit the operation of the responsive device free to be operated, meansfor preventing responsivev devices from being selected for operation,the selecting mechanism having contacts and said responsive deviceshaving contacts adapted for engagement with the aforesaid contacts, saidresponsive devices having the circuits controlling the same altered'when the contacts of responsive devices'free to be selected are engagedby the selector contacts and said meansmbeing in the form 'ot switchingdevices serving to render ineffective the'controlling circuits ofresponsive devices that are not to befree to be selected, and means Jforrestoring the opdition.

26. A telephone exchange system including lines extending from telephonestations to an exchange, a plurality of groups of operators linkconnectors at the exchange for uniting lines in conversation, a respon-`sive device tor each group 'of link connectors and common to the linkconnectors of such group, mechanism governed by calling to permit theoperation of the responsive device freeto be operated, meansfoi-preventing responsive devices from being operated, theaforesaidmechanism having contacts and p said responsive devices having contactsadapted forv engagement with the aforesaidl contacts, said responsivedevices having the circuits controlling the same altered when thecontacts of responsive the contacts and said means being in the form ofswitching devices serving to render ineffective the controlling circuitsof responsive devices that are not te be free to be operated, 'and meansfor restoring the operated responsive device to its normal condition.

27. A telephone exchange system includ-l ing lines extending fromtelephone stations to anexchange, a plurality of groups of operatorslink connectors-at the exchange, responsive devices'for said groups oflink connectors, and by calling lines adapted to select responsivedevices free 'for selection, said link connectors having operatorcontrolled means to adapt them to their telephone line joining functionindependently ot the aforesaid selecting mechanism.

28. A telephone exchange system including lines extending from telephonestations to an exchange, a plurality Aof groups otopto its normal confdevices i'ree. to be operated are engaged by selecting mechanismgoverned erators link connectors at the exchange, re-

sponsive devices for said groups of link connectors onecommon toconnectors of leach A craters link connectors at maltese adapt them 'totheir telephone line joining function independently of the' aforesaidSelecting mechanism. I

29. Af telephoneexchange system including lines extending fromtelephonestations to an exchange, a Vplurality of groups of -optheexchange, conductorsassociated With each group of connectors forconnecting operators telephones with calling lines, andselectingmechanism governed by calling lines adapted to selectconnectors free for selection, said link conductors having operatorcontrolled means toA adaptthem to their telephone line joining function'independentlyof the aforesaid se-v lecting mechanism.

30. A telephone exchange system including lines extending exchange, aplurality of groups of operators link connectors at the exchange,responsive devices for said groups of link connectors, selectingmechanism governed by calling lines adapted to select` responsivedevices free for selection, said link connectors having operatorcontrolled means to adaptthem to their telephone line joining functionindependently of the aforesaid selecting mechanism, and operatorcontrolled means for freeing said.responsive devices so that they may besubject to further selection.

3l. A telephone exchange system 'including lines extending fromtelephone stat-ions to an exchange, a plurality of groups'ofopmechanism, and` erators -link erators. link connectors at theexchange, re. sponsive devices for sald groups of link connectors onecommon to connectors of each group, selecting mechanismy governed bycalling lines `adapted to select responsive devices free for selection,said link connectors having operator controlled means to adapt them totheir telephone'line joining function independently of the aforesaidselecting operator controlled Imeans for freeing said responsiazedevices sov that they may be subject to further selection.

32. A telephone exchange system includtelephone stations Ito anexchange, a plurality of oups of operators link connectors at t eexchange,

conductors associated with each group of' tele'-l conn'ectors. forconnectingoperators phones With calling lines, selectinl mechanismgoverned seleetconductors free for selection, said link connectorshaving means to adaptthein to their .telephone pendently ofthe`aforesaid selectingme'chamsm, `and operator controlled means for'restoring-sani conductors .69 i' tion. l n 33. A.- telephone exchangesysteni includmgilines extendmg tolan exchange, a plurality sponsivevdevices lfor said groups-of link con#l meansto adapt them to theirtelephone line joining function independently of the aforesaid selectingmechanism.

ing lines extending from telephone stations to an exchange, a pluralityof groups of op'- erators link connectors at the exchange, responsivedevices. for said groups of link confrom telephone' stations to an lbycalling lines a apted toA liner joining function indes.l

to'selectable condif from telephone stations` connectors' at theexchange, lre-V -nectors, one common to connectors of each group,selecting-.mechanism governed by callfree forselection, and automaticmeans for guarding responsive devices when in selected conditions fromvfurther selection, said link connectors having means to adapt them totheir telephone line joining function independently of the aforesaidselecting mechanism. Y'

35. A telephone exchange system including lines extending from telephonestations toan exchange, a plurality of groups of operators liresponsivedevices for said groups of link by calling .lines adapted .to select"responsive devices free for selection, automatic means lectedconditions from further selection, said means to adapt them to theirItelephone line joining function independently of the afore- .ed 'conitions from further selection, ysaid said responsive to theirvtelephone'line joining function inr.dependentlv of the aforesaidselecting mech'- reeing said -responsiye devices so that they .may besubject Ato further selection.

, .3751A telephone exchange system includ- -ing lines extendingfromtelephone stations toen exchange, a pluralityof groups of operators?link connectors at the exchange, conductorsassociate'dwith each groupfor connecting operators telephones with callgoverned by.

further selection, said 'hnk connectors having operator controlled 34. Atelephone exchange system includ-- lng lines adapted to selectresponsive devices connectors, selecting mechanism governed linkconnectors having operator controlled sald selecting mechanism, andoperator conbe subject .to

link connectors havingl means to adapt themv anism, and. operatorcontrolled -means for ing lines, Selecting mechanism governed byv r,connectors at the exchange,

for guarding responsive devices when in se- "isc v free for selection,

are

afore- 'ing lines extending from telephone stations to -an exchange, aplurality of groups of operators link connectors at the exchange,conductors associated with each group for connecting operatorstelephones with calling lines, one common to connectors of each group,'selecting mechanism. governed by calling lines ,adapted to selectconductors automatic means for guarding such conductors when in selectedconditions from further selection, said link connectors having means toadapt them lto their telephone line joining function inde-` pendently ofthe aforesaid selecting mecha-- nism, and operator controlled .means forrestoring said conductorsl to selectable condition.

39. A telephone exchange system includinglines extending from telephonestations to an exchange, a plurality of linlr connectors at the exchangeadapted to the use of operators in making connections 1oetWeen lines,operators responsive devices, and selecting mechanism adapted to selectresponsive devices free for selection, said linlr connectors havingoperator controlled means to adapt them to their line joining functionindependently of the aforesaid selecting mechanism.'

40. A telephone exchange system including lines extendingy fromtelephone stations to an exchange, a plurality of linlr connectors atthe exchange adapted to the use of operators in making connectionsbetweenv lines, operators telephones, and selecting mechanism forselecting operators telephones free. for selection and associating themwith calling lines, said link connectors having operator controlledmeans to adapt them to their line joining function' independentlyot theaforesaid selecting mechanism.

41. A telephone exchange s'ys'tern including .lines extending fromtelephone stations to an exchange, a plurality of groups of operatorslink connectors at the exchange for uniting lines in conversation, aresponsive device for each group oi link connectors and common to thelink connectors ot such group, selecting devices individual to thetelephone lines' and operated byfcalling lines to select and permit' theoperation of the responsive device free to be operated. means fiorpreventing responsive devices from being selecte ed. for operation, theselecting devices having contacts and said responsive devices havingtheir telephone line incase@ aforesaid contacts, said having thecircuits controlling the same altered when the contacts ot responsivedevices free to be selected are engaged by the selector contacts andsaid means being in the form of switching devices serving to renderine'ective .the controlling circuits'of responsive devices that are notto be free to be selooted, and means for restoring the operatedresponsive device to its normal condition. j l

a2. A telephone exchange system including lines extending :tromtelephone stations to an exchange, a plurality of link connectors at theexchange adapted to the use-of operators in making connections betweenlines, operators responsive devic:v and automatically operatingelectro-magnetic switching mechanism for associating free responsivedevices with calling lines, said link connectors having operatorcontrolled means to adapt them to their 'line joining functionsindependently oi' said switching mechanism.

'43. A tele-phone system including lines extending rom telephonestations to an exchange, responsive devices c governingv the connectionof operators telephones with telephone lines at the exchange, and meansfor selecting an idle responsive device.

ai. A signaling system including 'a plurality ot signaling lines, signalreceivers. selector switches for selecting einmall receivers that aretree for select-ion and associating the same with signaling lines, andmeans'individual to the lines and which differ from. each other forcausing said signal receivers to give characteristic signals peculiar tothe lines. l

45. A signaling system including a plurality oi signaling lines`telephone receivers, selectorsivitches for selectingA telephonereceivers that are free for selection and associating the same withcalling lines, and phonographs individual to the lines and eachcapableof speaking the designation of the line to which it isindividual, said phonocontacts adapted for engagement with 'the lresponsive' devices loo ros

graphs serving to` operate the telephone repeivers to announce thedesignations ofthe mes. i I A telephone system including a plurality 'oftelephone lines extending to an exchange, signal receivers at differentoperators positions, selector switches operated by calling'telephonelines for selecting signal receivers that are free for select-ion andas-` sociating the same with calling telephone lines` and meansindividual to ,the lines and which diier from each other for causingsignals peculiar to the lines.

47. A telephone system including a. piu- 1 rality of i change, telephonereceivers at diierent op,av craters positions, selector switchesoperatedby calling telephone said signal receivers to givecharacteristic telephone lines extending to an er' lines for selecting12012.* 1u

and phono phone receivers that and associating the same with calling`lines each capab e of 'speakinothe designation of the line to which 1tis individual, said phonographs serving to operate the telephonereceivers to announce the designations ofthe lines.

48. A telephone system including a plu-.

rality of telephone lines extending to an exchange, signal receivers atdifferent operators positions, Vselector switches for selecting signalreceivers that are free for selection and associatingvthe same withcalling telephone lines, and means individual to the lines and Whichdiffer from each .other for causingsaid signal receivers to givecharacteristic signals peculiar to the lines.

49. A telephone system-including-a plurality of telephone lines.extending to an exchange, y'telephone receivers at different operatorspositions,. selector switches for selecting telephone receivers that arefree for selection and associating the same with calling lines, andphonographs individual to the lines andeach capable of speaking thedesignation of the lline to which it is individual, said phonographsserving to operate the telephone receivers to announce the designationsof the lines.

50,--A telephone lsystem having lines, a plurality of link connectorsfor making connections between lines, operators telephone outfits,mechanism for selecting an idle, operators telephone putit, and means toadapt the link connectors to their line joining function independentlymechanism.l

51. A telephone exchange system including lines extending fromQtelephonestations to an exchange, a plurality of link connectors at the exchangeadapted to the use of operators in making connections between lines,operators telephones, and automaticopie: of this patent may be Aobtainedfor ilve cents each, by addressing Vthe are free for; selectin aphs.individual to thevlines andKL of the aforesaid .ioperatingelectromagnetic switching msmf' for associating free operatorslelelihone's with calling lines, said link con- '.x'iec'tors having olerator controlled means to vadapt them'to t eir line joining functionsindependently'of said switching mechanism. 52. A ltelephone systemhaving lines, a .plurality of link connectors for making connectionsbetween lines, responsive devices, mechanism for selecting an idleresponsive device, and means to adapt the link connectors to their linejoining function independently of the aforesaid mechanism.

53. Atelephone exchange system includ.- ing -lines extending fromtelephone stations to an exchange, link connectors at the exchange .foruniting lines in conversation, operators telephone outfits associatedWith different operators positions, selecting mechanism governed bycalling lines for selecting idle operators telephone outfits, and meansoperating independently of link connectors for preventing selection ofoperators telephone outfits that are in selected condition. f

54.' A telephone exchange system includg lines extending from telephonestations to an exchange,-l1nk connectors at the exchange for unitinglines in conversation, operators responsive devices associated Withdifferent operatorspositions, selecting mechanism governed by 'callinglines for my name this 14th day of June, A. D., 1909.

ELMER R. CORWIN.

Witnesses t L. Gr. STRoH,

G. L. Cruce.

Commissioner of Patents.

Washington, D. C.

selecting-:idle operators responsive devices,

In Witness -whereof, I hereunto subscribeA

